Method of producing colored roofing



UNITED STATES PATENT OFFICE METHOD or PRODUCING COLORED noorme Jeremiah D. Giles, New York, N. Y.

No Drawing. Application December 13, 1935,

Serial No. 54,297

9 Claims. (c1. 91- 10) This invention relates to a method of producing colored roofing of the type comprising a main bbdy portion of felt which is impregnated with asphalt material in which are imbedded granules of mineral or ceramic material. The roofing made under this process may have a uniform color when the same is to be sold in roll form but when it is intended to be sold in cut pieces,

such as shingles or shingle strips, the roofing is 10 preferably, though not necessarily, made in two colorsor shades which blend gradually and irregularly into each other in such a way that when the material is laid on the roof it will have the appearance of an ornamental texture and will simulate deep shadows.

As is well known in the art, roofing of this kind is produced by a continuous process in which the felt is passed through a bath of the asphaltic material for impregnation; then coated with additional asphalt and finally the granules are sprinkled on this asphalt while still soft and are partly imbedded in the asphalt. When incorporating into this process a method of coloring, two particular difliculties' arise. One of these has to do with the tendency of the asphalt to bleed through the covering coating, and the other has to do with the iact that the coating must harden very rapidly or else it will interfere with the production of the machine and 30 greatly increase the cost of the product.

I have discoveredthat these difiiculties can.

manner and under such conditions that volatfle solvent is evaporated out of the material during the application so that the amount of heat withdrawn from the sheet in the form oflatent heat of vaporization is reduced, and such heat is left available to act to cause immediate polymerization of the coating material. Such an efi'ect can be had by applying the coating material to'the hot sheet through the medium of an atomizing sprayer, preferably the ordinary type of paint spray now in use in which a relatively large body of air is applied at the nozzle for the purpose of atomization. when such an apparatus is employed and the nozzle hept a reasonable distance from the sheet, say about 4 inches or more, it is possible to use a coating material well thinned down with solvent so that it will flow drops, and since only a limited amount of solvent remains to be evaporated off, the heat of the sheet will be found to be suflicient to cause the coating to harden in the-very short interval of time permitted by the usual operation of the machine. As is well recognized in the art, while roofing machines may travel at varying speeds, there is a relationship between the length of the web from the point where the granules are applied (after which my process must begin) to the end of the run where the web reaches the usual end point of its progress as a continuous web and is cut into pieces or rolled, and the rate of speed so as to give a time interval to permit the asphalt to harden. Actually the very short interval of time within which the coating must be hardened rarely will exceed tenminutes and usually this time is less than that. The usual temperature of the sheet when the granules are applied is in the order of about 300 F. (which may be lowered somewhat by the cooling eifect of the granules) and due to the short length of time available it is obvious-that as much as possible of this heat should be taken advantage of to harden my coating.

As regards the type of coating employed, I have found that one should use a coating comprising a synthetic resin of the heat-hardening type and a drying 011. These are preferably incorporated together with heat or else the drying oil is given a preliminary treatment so that it is more or less polymerized before beingapplied.

'The resin and the, drying oil may be combined chemically as inthe case of the modified alkyd resins such for example as those disclosed in Kienle Patent No. 1,893,875, or they may simply be fluxed together as is probably the case with certain-of the known combinations of phenolic resins and drying oils. As regards the drying oil used, I have had the best results when using all or a substantial percentage of tung oil, but apparently goodresults may be obtained by the use of other drying oils such as linseed oil. The important feature is that the coating taken as a with the hot asphalt either at the time of appli- 'whole must be one which can be hardened rapid- I bleeding takes place.

cation or later during use. In some cases this thermal hardening will be caused by the poly-- merization (setting-up) of the resin itself, or, as in the case of the modified alkyd resins referred to, it may be caused by a polymerization of the compound molecule of resin and drying oil which in that instance is known to harden at lower temperatures and very much more rapidly than is the case with the unmodified resins.

Apparently when such a coating diluted with a volatile solvent such as petroleum ether is applied to the hot sheet through the use of an atomizer as specified, a large percentage of the solvent is volatilized duringthe application before it strikes the surface, so that the coating does not materially dissolve the surface of the asphalt to cause a bleeding, but since the asphalt is still soft the coating compound does form an exceedingly dense and close bond with the asphalt material and the granules. Further, it appears that the heat of the asphalt drives ofi any residual solvent before the latter penetrates the asphalt, thus avoiding bleeding during the application; and the coating is either immediately or by progressive polymerization rendered sufflciently infusible and insoluble so that later under the conditions of exposure no material Also it will be found that the application'of this coating greatly increases the life of the product, for the coating tends to lock the granules in place.

The coating may be applied in the form of a substantially transparent varnish or enamel but preferably it is compounded with an appropriate pigment or other coloring matter such as a dye or lake. In view of the fact that the coating is to be subjected to substantial temperatures, a pigment or color should be selected which will withstand temperatures up to at least 250 F.

My invention may be employed for applying a uniform color to an entire sheet of roofing but preferably I produce a preliminary sheet having two tones by applying the color in bands either over the uncoloredsheet or over a sheet which has been wholly or partly covered, with a first coatof a contrasting color or tone, though the latter is not ordinarily feasible-by my prefered continuous process, as there is not sufficient heat in the sheet to set-up two coats of coloring matter without special provision for drying and hardening. When colored bands are applied, it is very important that the edges should not be sharp or even, but that the different bands should blend together gradually and irregularly to give the finished product an appearance of natural age or irregularity when applied to the roof. (Such an effect is produced through the use of the spray apparatus as described, which form bands which diminish in intensity towards their edges, and the effect may'be increased by giving some movement to the spraying apparatus during the application either through manual or mechanical means, or the sheet itself may be given some ioggling movement by an appropriate mechanism. For example, the sheet may be moving vertically when the spray is being applied and may be tapped intermittently to cause it to move from or towards the spraying apparatus. When the roofing is made in two tones or colors, it ordinarily is cut up afterward as for example in the form of shingles or shingle strips.

My invention may be readily understood from the following examples:

100 pounds of oil-soluble phenol-formaldehyde resinwereiluxed-withriogslionsoftungoilto which were added 5 pounds of litharge and '12 gallons of a volatile thinner such as petroleum spirits. With the coating or enamel thus prepared was incorporated slightly less than an equal weight of a heat-resistant pigment. This coating material was applied in the ordinary course of manufacture of roll roofing by the use of spray guns mounted'with their nozzles about 8 inches from the sheet and arranged so as to apply a thin but uniform coating over the entire sheet. During the application substantial amounts of volatile solvent were driven off, as was readily apparent by the nature of the atmosphere surrounding the operation. The coating hardened rapidly and the material was ready to be rolled up at the end of the usual operations without in any way slowing up production.

In another instance, the granules selected were of a color and tone suitable for the darker portions of the shingles. The coating material was prepa ed of a similar color but of a lighter shade. In this case the coating was applied in narrow bands throughout the length of the sheet and spray guns were employed mounted on spring mountings so that they could be agitated during the course of application. It is to be understood that the spray guns used were equipped, as usual, with compressed air which mixed with the coating at the nozzle to atomize it. In this case, as a relatively narrow band was desired, the guns were positioned about 4 inches from the sheet. This application resulted in the production of bands running lengthwise of the sheet which merged gradually and irregularly into the darker background color. The sheets were subsequently out into strip shingles in such a way that the butt portions (exposed ends) were covered with the lighter color and within the area that normally would be exposed this light color gradually and irregularly merged into the darker ground color. In this way the colored surface was all utilized in the most exposed portion of the shingle and the desired two-toned eflect was produced in a single operation.

When shingles produced according to this second example are applied to a roof, the effect is entirely different from that which would be produced by a roofing of uniform color, or by applying roofing elements having sharp bands of darker material running across them, for these dark bands give a decidedly artificial appearance and not the naturalistic shadows desired. Actually, by employing this invention, a roof formed with relatively thin shingles made in accordance with my invention has the appearance of a roof made with shingles of very substantial thickness.

. In other words, this color eflect serves to give the impression that shingles of much greater body are being used than is the fact; and thus one of the principal architectural criticisms of the asphalt shingle is overcome. If the color arrangement is reversed so that the darker color is at the butts, the effect of thickness is not so pronounced, but even in that case an interesting texture is given to the roof and the darker colored tones merge gradually and irregularly with the lighter ones. giving an appearance of weathering which is often much desired by architects. It will also be found that the coating which has been set-up in situ follows the contour of the rough surface formed by the granules and penetrates between the granules to the asphalt with whichitbondssothatthegranulesarenrmly anchored in place and there is no substantial vent, such enamel being in condition to be transtendency of the asphalt to bleed through the finished coating? While the examples given above illustrate my invention, it is to be understood that I do not intend to limit myself in any way to the specific ingredients or the proportions given. Also, other types of thermo-setting resins and drying oils may be employed. when I refer to a thermosetting coating I intend to imply that the coating is such thatunder the conditions of heating here'- in set forth it will change from a soluble .to a sumcientiy insoluble form so that it will not then blend with the asphalt. This is particularly true of the phenolic resin coatings.

This application is a continuation in part of my earlier application Serial No. 642,458, filed Nov. 12, 1932.

What I claim is:

1. In the process of manufacturing sheet bituminous building material which includes the steps of continuously impregnating a web of fibrous material with asphalt, coating it with additional melted asphalt material and permitting such asphalt material to harden and subsequently cutting the web up for packing, the step of spraying onto such web after said coating operation and while the web is still hot, an enamel comprising a thermo-setting resin selected from the group consisting of the phenol-formaldehyde resins and a the alkyd resins, a drying oil which has been given a preliminary heat treatment so that it will undergo rapid polymerization, and a volatile solformed by the heat of the web acting to set up the resin and polymerize the oil to a sufiicient degree to prevent the'sticking together of superimposed the resin is a phenol-formaldehyde resin.

3. A process as specified in claim 1 which also includes the step of embedding, granules in the asphalt coating, after which the enamel is applied.

4. A processas specified in claim 1 in which the enamel is applied in bands covering inthe aggregate less than all of the web.

5. A process as specified in claim 1 in which given a preliminary heat treatment so that it will undergo rapid hardening when heated, and a volatile solvent, such enamel being in condition to lie-transformed rapidly to a substantially insoluble. state by the heat of the bituminous material acting to set up the resin and polymerize the oil and making such application under such conditions that the solvent is evaporated sufficiently rapidly and the body of the enamel is caused to harden sufllciently. rapidly by the heat of the bituminous material so that no substantial bleeding of the bituminous material into the enamel coating will take place.

7. A process as specified in claim 6 in which the resin is a phenol-formaldehyde resin.

8..A method as specified in claim 6 in which the enamel. issprayed onto the bituminous surface while the same is sufiiciently hot so that its heat initiates evaporation of solvent before the enamel strikes the surface of the bituminous material.

9. The process as specified in claim 6 in which the enamel is colored and is applied in bands covering only a part of the bituminous surface.

' JEREMIAH D. GILES. 

